Prefabricated stair



Feb. 27, 1968 w. F. SIVLEY 3,370,387

Y PREFABRICATED STAIR Filed April l, 1966 v INVENTOR.

United States Patent O 3,370,387 PREFABRICATED STAIR William Fred Sivley, Rte. 2, Box 274, Pinson, Ala. 35126 Filed Apr. 1, 1966, Ser. No. 539,435 Claims. (Cl. 52-188) ABSTRACT 0F THE DSCLOSURE A prefabricated stair having horizontal tread members secured rigidly between stringers. Upper and lower vertical riser sections are adjustably connected to each other with the lower riser Vsection being rigidly connected at its lower end to its tread member and the upper riser section being rigidly connected to a superjacent tread member.

This invention relates to a prefabricated stair and more particularly to an adjustable step unit for a stair which permits adjustment of the effective height of the riser whereby the vertical space between adjacent treads may be varied at the time the stair is installed.

A more specific object of my invention is to provide an adjustable step unit for a stair in which the riser shall embody interlocked upper and lower sections which are adjustable relative to each other whereby they may be secured rigidly to each other at selected positions.

A further object of my invention is to provide an adjustable step unit of the character designated which shall be particularly adapted for use in the building of stairs having the treads thereof covered with a filler material, such as concrete and the like.

A further object of my invention is to provide a step unit for a prefabricated stair of the character designated in which the adjustable portion of the riser is completely out of view after installation, thus improving the appearance of the completed stair.

A further object of my invention is to provide a prefabricated stair of the character designated which shall include screed members which permit proper leveling of the filler material after installation.

A still further object of my invention is to provide a step unit for a prefabricated stair of the character designated which shall be simple of construction, economical of manufacture and one which may be readily installed by unskilled labor due to the fact that the step units may be adjusted at the time of installation.

Heretofore in the art to which my invention relates, difficulties have been encountered in the construction and installation of prefabricated stairs since the riser sections had to be of the exact height to lit a particular installation. The provision of a series of vertically spaced openings in the riser which permit the riser to be attached at selected positions to stringers permits some adjustment at the time of installation, but does not permit adjustment to any desired location due to the fact that the riser must be attached at a particular opening position. Also, such openings in the riser section mar the appearance of the riser.

In accordance with my invention, I provide a riser having upper and lower sections which are interlocked for vertical adjustment relative to each other whereby the riser sections may be secured rigidly to each other at a selected position and at the same time the break line between the interlocked sections of the riser does not affect the appearance of the completed stair. To aid in the leveling of the filler material applied to the tread section, I provide an upstanding screed member adjacent and forwardly of the riser which forms a part of the composite stair after installation.

3,370,387 Patented Feb. 27, 1968 A step unit for a prefabricated stair and embodying features of my invention is illustrated in the accompanying drawing, forming a part of this application, in which:

FIG. l is a vertical sectional view through a plurality of step units;

FIG. 2 is a fragmental view taken generally along the line 2--2 of FIG. l; and

FIG. 3 is an enlarged, sectional view through a riser and the tread members connected thereto, the upper section of the riser and the tread member connected thereto being shown in an unadjusted dotted line position.

Referring now to the drawing for a better understanding of my invention, my improved step unit is mounted between a pair of laterally spaced stringers indicated generally at 1t). Since the stringers may be in the form of conventional type channel members usually used in the installation of stairs, no further description thereof is deemed necessary. The upper ends of the stringers 1t) may be secured to a box-like header 11 in the usual manner.

Horizontal tread members 12 extend between the stringers 10 and are secured thereto by suitable means, such as by welding an angle member 13 to the upper surface of the tread member 12 and then securing the vertical flange of the angle 13 to the Stringer 10 by bolts 14.

Formed integrally with the rear edge of each tread member 12 is a lower, generally vertical riser section 16 which also extends between the stringers 1). A depending flange 17 is carried by the upper end of the lower riser section 16 and extends downwardly in spaced relation to the lower riser section, as shown in FIGS. 1 and 3. That is, the upper portion of the lower riser section 16 is bent on itself to define the depending flange 17, as shown.

Extending between the stringers 1t) adjacent and forwardly of the lower riser section 16 is an upper, generally vertical riser section 18. An upstanding flange 19 is carried by the lower end of the upper riser section 18 and extends upwardly in spaced relation to the upper riser section 18 4between the depending flange 17 and the lower riser section 16. Accordingly, the anges 17 and 19 are interlocked and adapted for sliding movement relative to each other whereby the effective height of the riser may be varied. The riser sections 15 and 18 are rigidly secured to each other after final adjustment has been made by suitable means, such as by welding at 21. Since the weld 21 is at the rear side of the riser section 18, it is completely out of view whereby it does not affect the appearance of the completed stair.

The yupper portion of the upper riser section 18 extends outwardly and upwardly as at 22 and then vertically as at 23 to define a forward wall for a recess which receives the filler material 24, which may be in the form of concrete or the like. The upper edge of the vertical portion 23 is provided with an inturned flange 26 which denes a screed element. Extending between the stringers 10 adjacent and forwardly of the riser sections 16 and 18 is an upstanding member 27 having a forwardly extending flange 28 at the upper end thereof which also defines a screed element. As shown in FIG. 1, the screed elements 26 and 2S are at the same level whereby they determine the level of the upmr surface of the filler material 24. Since the upstanding member 27 is forwardly of the adjustable riser sections 16 and 18, the riser sections may be moved to selected positions relative to each other even after the iiller materials 24 have been added.

An upwardly and forwardly extending ange 29 is provided at the forward end of the tread member 12 in position to extend alongside the upwardly and forwardly extending portion 22 of the upper riser section 1S. The

ange 29 is secured to the upper riser section 1S by suitable means, such as by welding at 31.

From the foregoing description, the construction of my improved stair will be readily understood. The tread members 12 are positioned between the laterally spaced stringers and are secured thereto, as described hereinabove, by the bolts 14. The upwardly and forwardly extending anges 29 carried by the tread members 12 are secured to the upper ends of the riser sections 18, as

Y adjusted automatically to accommodate the space between adjacent tread members 12, With the riser sections 16 and 13 thus adjusted to the proper position relative to each other, the riser sections aresecured rigidly to each other by welding at 21 to thus provide a composite, rigid riser. With the treads and risers thus mounted between the stringers 10, the filler material, such as concrete, is poured Vinto the recess between the upstanding member 27 and the upper portion of the upper riser section `18, as shown. ln View of the fact that the screedelements 26 and 28 are at the same height, the concrete material may be readily screeded to provide a complete stair.

From the foregoing, it will be seen that I have devisedk an improved step unit for a Prefabricated stair. By providing riser sections which are adjustable relative to each other without the necessity of providing openings and securing bolts,-the effective height of the riser may be readily varied at the time of installation and at the same time the adjusting means is completely hidden from view. Also, by providing the opstanding member27 adjacent and forwardly of the riser, I not only provide an eective screed element which forms la part of the composite stair but 'prevent the filler material from entering the space subjacentl the interlocked portion of the riser sections. `Furthermore, by providing an adjustable riser in which the break line between the sections thereof is below the surface of the ller material, there is no break line in the exposed surface of the riser after installation.

While I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modications without departing from the Vspirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are specifically set forth in the appended claims.

What I claim is: 1. In a step unit for a Prefabricated stair having stringers spaced from each other:

(a) a horizontal tread member extending between said stringers, (b) means to secure said tread member rigidly to said stringers,

between said stringersand Connected at its lower end to said tread member,

(d) a depending vertical flange-like member carried by the upper end of said lower riser section and extending downwardly in spaced relation to said lower riser section, l

(e)V an upper generally vertical riser sectionextending between said stringers and adapted to be secured rigidly to a forward portion of a superjacent tread member prior to adjustment of said upper and lower riser sections relative to each other.

(f) an upstanding flange-like membercarried by the lower end of said upper riser'section and vextending upwardly in spaced relation to saidupper riser sectionbetween said depending ange and said lowerV riser section, and 1 g) -means to secure said lower riser section to said up-k y per riser section at selected positions relative to each other.

2. The step unit as defined in claim 1 in which said forward portion of said tread member vextends upwardly and forwardly alongside an upwardly and forwardly. ex,- tending portion of a subjacent upper riser section and is secured rigidly thereto.

3. The step unit as defined standing screedmember is carried by said tread membe adjacent and forwardly of said riser sections.y

4. The step unit as defined in claim 3 ii'iwhich afor .Y i wardly extending ange is carried by the upper edge of said screedV member and a rearwardly extending ange is carried by the upper edge of a subjacent upper riser section in position to cooperate Vwith said forwardly extending flange and define spaced apart screed surfaces with a recess therebetween for receiving a filler material.

5. The step unit as dened in claim 1 in which said lower riser section is formed integrally with said tread v Theisen 52-188 FRANK L. ABBOTT, Primm Examiner.

R. A. STENZEL, CHARLES G. MUELLER,

j Assistant Examiners.

inrclaim 1 in which an up-V 

